JPH1054823A - Method and apparatus for recognizing molecule - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify necessary operations, eliminate the need for preparing many kinds of reagents and surely recognize molecules, by recognizing molecules based on a cyclic voltammogram. SOLUTION: A solution including molecules to be measured is dropped onto an electrode main body 1 of a conductive substance, and a voltage is impressed between a pair of electrodes of the main body 1. The voltage is increased or decreased with a predetermined rate by a potentiostat (voltage sweep means) 2. A graph formation part 3 forms a cyclic voltammogram with the use of inputs of the impressed voltage from the potentiostat 2 and a current taken out from the main body 1. A recognition part 4 receiving an input of the formed cyclic voltammogram carries out a predetermined process (pattern-matching, etc.) and outputs a recognition result of molecules (solid isomer recognition result). In this manner, molecules can be simply and surely recognized without requiring a dilution process or the like, and even a concentration of molecules can be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for recognizing a molecule, and more particularly to a method and an apparatus suitable for recognizing a stereoisomer of a sugar represented by the same molecular formula.

[0002]

2. Description of the Related Art Conventionally, as a method for specifying a substance having many kinds of stereoisomers, particularly a kind of sugar, an optical rotation (po) is used.
A method for measuring the ligation (see Kirk Osmer Vol. 21, p. 871) is known. As a method for measuring the type and amount (concentration) of a substance having a large number of stereoisomers, in particular, a sugar, a titration method (Lane a
ndEynon Method, Kirk Osmer Vo
l. 21, p. 873).

[0003]

However, when a method for measuring the optical rotation is adopted, a sugar solution having a high concentration of 1.44 mol / l is required. And 1.44mo
In order to obtain a sugar solution having a high concentration of 1 / l, it is necessary to perform a concentration treatment or the like, which disadvantageously complicates the operation. Specifically, the concentration process
Unlike the dilution process, this is a process that reduces the amount of the solution.Thus, compared to the dilution process that requires only adding a solution, the reduction in the amount of the solution cannot be achieved in a short time, and if the concentration ratio is high, The amount of solution to be reduced is significantly increased.

In addition, the titration method is based on the principle that a predetermined color is recognized when the amount of the sugar solution dropped reaches a predetermined amount, so that it depends on the type of stereoisomer. And various kinds of reagents are required. Therefore,
The operation of preparing various kinds of reagents is required, and a predetermined amount of the sugar solution must be dropped for each reagent, so that the operation becomes extremely complicated.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and can greatly simplify the necessary work, and does not require preparing various kinds of reagents.
Moreover, it is a first object of the present invention to provide a method and an apparatus for recognizing a molecule capable of reliably recognizing a molecule, and to provide a method and an apparatus for recognizing a molecule capable of detecting the amount of a molecule. The purpose is.

[0006]

According to a first aspect of the present invention, there is provided a method for recognizing a molecule, the method comprising: continuously applying a voltage increasing or decreasing at a predetermined rate to an electrolyte solution containing a molecule to be measured; And recognizing the molecule based on the shape of the obtained cyclic voltammogram.

The molecular recognition method according to a second aspect is a method in which an electrolyte solution is used as the solution containing the molecules to be measured. In the molecular recognition method according to the third aspect, a cyclic voltammogram shape is obtained in advance for each of the molecules, and it is determined which cyclic voltammogram shape matches the obtained cyclic voltammogram shape. However, this is a method of recognizing a molecule based on the determination result.

According to a fourth aspect of the present invention, there is provided a method for detecting a concentration of a molecule on the basis of an area value of an upward projection of the cyclic voltammogram obtained. The molecular recognition device according to claim 5, wherein a voltage is applied to the electrolyte solution containing the molecules to be measured, and an electrode means for taking out a current in this state, a voltage sweep means for increasing or decreasing the voltage at a predetermined rate, It includes visualization means for obtaining a cyclic voltammogram based on the voltage and the extracted current, and recognition means for recognizing a molecule based on the shape of the obtained cyclic voltammogram.

[0009] The molecular recognition device according to claim 6 employs an electrolyte solution as the solution containing the molecules to be measured. Claim 7
The molecular recognition device of the present invention, as the recognition means, previously obtains the shape of a cyclic voltammogram corresponding to each of the molecules, and the shape of the obtained cyclic voltammogram matches with which cyclic voltammogram shape. Is determined, and a molecule that recognizes a molecule based on the determination result is adopted.

[0010] The molecular recognition device according to claim 8 further includes a concentration detecting means for detecting the concentration of the molecule based on the area value of the upward projection of the obtained cyclic voltammogram.

[0011]

According to the molecular recognition method of the present invention, a voltage that increases or decreases at a predetermined rate is continuously applied to a solution containing a molecule to be measured, and in this state, a current is taken out to obtain a cyclic voltammogram. Because it recognizes molecules based on the shape of the cyclic voltammogram
The molecules can be easily and reliably recognized without the need for a dilution treatment or the like, and without the need for various reagents.

According to the molecular recognition method of the second aspect, when the molecule to be measured is a monosaccharide, the decomposition of the monosaccharide can be promoted, and the same effect as that of the first aspect can be achieved. . According to the molecular recognition method of claim 3, the shape of the cyclic voltammogram is obtained in advance for each molecule, and the shape of the obtained cyclic voltammogram matches with the shape of the cyclic voltammogram. Is determined, and the molecule is recognized based on the result of the determination. Therefore, the same operation as that of claim 1 or claim 2 can be achieved.

According to the molecular recognition method of the present invention, the concentration of the molecule is also detected based on the area value of the upward projection of the obtained cyclic voltammogram. In addition to the above-mentioned effects, the concentration of the molecule can be easily and reliably detected.
In the case of the molecular recognition device according to claim 5, by the electrode means,
A voltage is applied to the solution containing the molecules to be measured, and a current is taken out in this state. Then, the voltage is increased / decreased at a predetermined rate by voltage sweep means, a cyclic voltammogram is obtained by the visualization means based on the current taken in accordance with the increase / decrease of the voltage, and the obtained cyclic voltammogram is obtained by the recognition means. Recognize molecules based on shape. Therefore, there is no need for dilution, etc., and no need for various reagents.
In addition, molecules can be reliably recognized.

According to the molecular recognition device of the present invention, when the molecule to be measured is a monosaccharide, the decomposition of the monosaccharide can be promoted, and the same operation as that of the present invention can be achieved. . In the molecular recognition device according to claim 7, as the recognition means, a cyclic voltammogram shape is obtained in advance in correspondence with each of the molecules, and the obtained cyclic voltammogram shape is any of the cyclic voltammograms. Since it is determined whether the shape matches the shape and the molecule is recognized based on the result of the determination, the same operation as in the fifth or sixth aspect can be achieved.

According to the eighth aspect of the present invention, the molecular recognition apparatus further comprises a concentration detecting means for detecting the concentration of the molecule based on the area value of the upward projection of the obtained cyclic voltammogram. In addition to the effect of any of the fifth to eighth aspects, the concentration of the molecule can be easily and reliably detected.

[0016]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing one embodiment of the molecular recognition device of the present invention. The molecular recognition device applies a voltage between an electrode body (electrode means) 1 having an electrode made of a conductive substance and a pair of electrodes of the electrode body 1, and increases or decreases the applied voltage at a predetermined rate. Ostat (voltage sweeping means) 2, a graph creating unit (visualizing means) 3 for creating a cyclic voltammogram using the voltage applied by the potentiostat 2 and the current extracted from the electrode means 1 as inputs. A recognition unit 4 that performs predetermined processing (such as pattern matching processing) using the cyclic voltammogram as input and outputs a molecular recognition result (stereoisomer recognition result).

The electrode body 1 comprises two or three electrodes (working electrode, counter electrode or working electrode,
Each of the electrodes, particularly the working electrode, can be made of a noble metal (platinum, gold, iridium, rhodium, etc.) or one made of a noble metal alloy. When electrodes are employed, the electrode body 1 can be used repeatedly. However, when the electrode body 1 is used only once, each electrode can be made of iron, cobalt, nickel, or the like. As the counter electrode, for example, one made of silver is employed. When a platinum electrode is used as the working electrode, for example, the electrode has an area of 0.227 cm ^2.
May be used.

The potentiostat 2 adjusts the voltage applied between the pair of electrodes to, for example, 50 mV / sec.
, Then decrease at the same rate and increase again at the same rate. The graph creation unit 3
With the applied voltage by the potentiostat 2 and the current taken out of the electrode body 1 as inputs, for example, the horizontal axis is the applied voltage (potential with respect to the potential of the target substance),
This is to create a cyclic voltammogram in which the vertical axis is the extracted current.

The recognizing unit 4 holds a cyclic voltammogram of a stereoisomer containing a substance to be recognized (recognition target molecule) as a reference cyclic voltammogram in advance, and stores the cyclic voltammogram generated by the graph preparing unit 3. It is determined which reference cyclic voltammogram matches, and a recognition result is output in response to this determination result. However, it is preferable that the reference cyclic voltammogram be retained in advance in correspondence with the type and concentration of the stereoisomer.

[0020]

EXAMPLES 0.1 M (= 100 mM = 0.1 mol /
1) Seven types of aqueous solutions of the monosaccharide are prepared. The monosaccharide is C
_Although represented by the molecular formula of ₆ H ₁₂ O ₆ , it is known that there are 16 or more stereoisomers. Then, among these stereoisomers, seven easily available stereoisomers (D
-Glucose, D-mannose, D-galactose, D
-Talose, D-allose, D-fructose).

Then, the aqueous solution of each monosaccharide is dropped on the electrode body 1. Here, the amount of the aqueous monosaccharide solution to be dropped is 30 μl, and the same amount of the electrolytic solution is further dropped. Here, the reason why the electrolytic solution is dropped is to promote the decomposition of the monosaccharide. In addition, the order of dropping the monosaccharide aqueous solution and the electrolytic solution may be any order, or a mixture of both may be dropped in advance.

In this state, the potentiostat 2
To apply a voltage of 50 mV / sec to the electrode body 1 using
, Then decrease at the same rate,
By repeatedly increasing and decreasing the applied voltage, a standard cyclic voltammogram was obtained for each of the stereoisomers, and D-glucose, D-mannose, D-glucose were obtained.
The cyclic voltammograms shown in FIGS. 2 to 7 can be obtained for each of galactose, D-talose, D-allose, and D-fructose. Note that FIG.
The cyclic voltammogram of FIG.
2 shows a case where the increase and decrease of the applied voltage with respect to are repeated twice. Then, among the cyclic voltammograms, the graph shown in (A) (upper graph in the cyclic voltammogram) corresponds to the increase in applied voltage, and the graph shown in (B) (in the cyclic voltammogram) , Lower graph) corresponds to the decrease in the applied voltage. As is clear from these cyclic voltammograms, the graph corresponding to the increase in the applied voltage shows a high agreement between the first and second times, whereas the graph corresponding to the decrease in the applied voltage is 1 A large variation is shown between the second time and the second time. Therefore,
It is preferable to adopt only the upper graph of the cyclic voltammogram, not the entire cyclic voltammogram, as the reference cyclic voltammogram, and it is possible to increase the recognition probability of the stereoisomer.

Therefore, thereafter, an aqueous solution (100 mM) containing an unknown monosaccharide and an electrolytic solution are dropped on the electrode body 1 to obtain a cyclic voltammogram in the same manner, and matching with the reference cyclic voltammogram is performed. Thereby, recognition of an unknown monosaccharide can be achieved. Here, being a stereoisomer of a monosaccharide,
It can be confirmed by measuring general properties as a monosaccharide.

In the above description, the concentration of the monosaccharide is set to 100 mM, but may be set to a range of 1M to 0.01M. Further, the electrolyte may be acidic, alkaline, or neutral. 8 to 11 show that the concentrations of the D-glucose aqueous solution were 30 mM, 20 mM, and 10 mM, respectively.
It is a figure which shows the cyclic voltammogram obtained by setting these M and 5 mM and dripping these aqueous solutions on the electrode main body 1.

The cyclic voltammogram of the D-glucose aqueous solution typically has, for example, the shape shown in FIG. 12, and three peaks A, B, and C are obtained as oxidation peaks. Among these, the area of a portion (shaded portion) surrounded by a curved portion including the two upward peaks B and C at the center and a tangent at the base of the curved portion is an oxidized charge amount,
When the amount of oxidized charge was calculated in accordance with the four types of D-glucose concentrations, as shown in FIG. 13, it was found that the linearity was high with respect to the D-glucose concentration. Therefore, when a cyclic voltammogram is obtained, stereoisomers can be recognized by matching with the reference voltammograph as described above,
In addition, by calculating the sum of the areas of the portion surrounded by the curved portion including the peaks B and C and the corresponding tangent,
The concentration of the stereoisomer can be measured.

The present invention can of course be applied to the recognition of stereoisomers of substances other than monosaccharides.
Of course, it can be applied to these concentration measurements. For example, a cyclic voltammogram of 0.5 mM uric acid (0.5 mM is almost the maximum concentration of uric acid in blood) is as shown in FIG. 14, and 0.1 mM ascorbic acid (0.1 mM is in blood). The cyclic voltammogram of the concentration of ascorbic acid (not less than the maximum value of ascorbic acid) is as shown in FIG.

[0027]

According to the first aspect of the present invention, there is provided a unique effect that a molecule can be easily and reliably recognized without the need for a dilution treatment or the like, and without requiring various kinds of reagents. The invention of claim 2 has a unique effect that, in addition to the effect of claim 1, when the substance to be measured is a monosaccharide, the decomposition of the monosaccharide can be promoted.

The third aspect of the invention has the same effect as the first or second aspect. The invention of claim 4 is claim 1
In addition to the effect of any one of the third to third aspects, a unique effect that the concentration of a molecule can be detected easily and reliably can be obtained. The invention of claim 5 has a unique effect that the molecule can be easily and reliably recognized without the need for a dilution treatment or the like and without the need for various kinds of reagents.

The invention of claim 6 has a specific effect that, in addition to the effect of claim 5, when the substance to be measured is a monosaccharide, the decomposition of the monosaccharide can be promoted. Claim 7
The present invention has the same effect as the fifth or sixth aspect. The invention of claim 8 has a unique effect that the concentration of a molecule can be easily and reliably detected in addition to the effect of any of claims 5 to 7.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing one embodiment of a molecular recognition device of the present invention.

FIG. 2 is a diagram showing a cyclic voltammogram of D-glucose.

FIG. 3 is a diagram showing a cyclic voltammogram of D-mannose.

FIG. 4 is a diagram showing a cyclic voltammogram of D-galactose.

FIG. 5 is a diagram showing a cyclic voltammogram of D-talose.

FIG. 6 is a diagram showing a cyclic voltammogram of D-allose.

FIG. 7 is a diagram showing a cyclic voltammogram of D-fructose.

FIG. 8 is a diagram showing a cyclic voltammogram obtained by setting the concentration of a D-glucose aqueous solution to 30 mM and dropping the aqueous solution onto an electrode body.

FIG. 9 is a diagram showing a cyclic voltammogram obtained by setting the concentration of a D-glucose aqueous solution to 20 mM and dropping the aqueous solution onto an electrode body.

FIG. 10 is a diagram showing a cyclic voltammogram obtained by setting the concentration of a D-glucose aqueous solution to 10 mM and dropping the aqueous solution onto an electrode body.

FIG. 11 is a diagram showing a cyclic voltammogram obtained by setting the concentration of a D-glucose aqueous solution to 5 mM and dropping the aqueous solution onto an electrode body.

FIG. 12 is a diagram schematically showing a cyclic voltammogram of a D-glucose aqueous solution.

FIG. 13 is a graph showing the relationship between D-glucose concentration and oxidized charge.

FIG. 14 is a view showing a cyclic voltammogram obtained by setting the concentration of a uric acid aqueous solution to 0.5 mM and dropping the aqueous solution onto an electrode body.

FIG. 15 is a diagram showing a cyclic voltammogram obtained by setting the concentration of an aqueous solution of ascorbic acid to 0.1 mM and dropping the aqueous solution onto an electrode body.

[Explanation of symbols]

 Reference Signs List 1 electrode body 2 potentiostat 3 graph creation unit 4 recognition unit

Claims (8)

[Claims] 1. A voltage that increases or decreases at a predetermined rate is continuously applied to a solution containing a molecule to be measured. In this state, a current is taken out to obtain a cyclic voltammogram, and based on the shape of the obtained cyclic voltammogram. A molecular recognition method comprising recognizing a molecule. 2. The method according to claim 1, wherein the solution containing the molecules to be measured is an electrolyte solution. 3. A cyclic voltammogram shape is obtained in advance corresponding to each of the molecules, and it is determined which cyclic voltammogram shape matches the obtained cyclic voltammogram shape. The molecular recognition method according to claim 1 or 2, wherein the molecule is recognized based on the result. 4. The molecule recognition method according to claim 1, wherein the concentration of the molecule is also detected based on the area value of the upward protrusion of the cyclic voltammogram obtained. 5. An electrode means (1) for applying a voltage to a solution containing molecules to be measured and extracting current in this state, and a voltage sweep means (2) for increasing or decreasing the voltage at a predetermined rate. A visualization unit (3) for obtaining a cyclic voltammogram based on the applied voltage and the extracted current; and a recognition unit (4) for recognizing a molecule based on the shape of the obtained cyclic voltammogram. Molecular recognition device. 6. The molecular recognition device according to claim 5, wherein the solution containing the molecules to be measured is an electrolyte solution. 7. The recognizing means (4) obtains a cyclic voltammogram shape corresponding to each molecule in advance, and matches the shape of the obtained cyclic voltammogram with any cyclic voltammogram shape. The molecular recognition device according to claim 5, wherein it is determined whether or not to perform recognition, and the molecule is recognized based on a result of the determination. 8. The apparatus according to claim 5, further comprising a concentration detecting means for detecting a concentration of a molecule based on an area value of the upward projection of the obtained cyclic voltammogram.
The molecular recognition device according to any one of the above.